mark neidorff composed on 2023-03-30 13:30 (UTC-0400):
*Background*: Just for the record, I started using OpenSUSE with 10.3. I have been pleased and you folks who help are great.
I have avoided UEFI for as long as I can. My old computer died a sudden death and the time has come to deal with UEFI. Fortunately for me, almost 2 years ago I came across a Dell XPS 8940, with NVMe and SSD drives, high end graphics (I'm not a gamer, so that's not a big deal for me), and the usual other bells and whistles. The deal was good because it was a return, so it has sat. I did try to install OpenSUse (don't remember the version, but it did support UEFI) but that did not go well. I looked for docs on UEFI, but they seemed to be non-existent. Now that I am "in a corner" I want to go back and see if I can get Leap 15.4 installed on this computer. I downloaded the UEFI version and have it on a DVD, so I am ready. My goal is to boot and run OpenSuse from the NVMe drive and use the SSD drive as a data backup dirve--but I will listen to any other suggestions. *Main question: * When I tried the install the first time, I noticed that drive and partition designation (for a start) were completely different under UEFI. Is there "non-technical, human readable" documentation that can walk me through repartitioning, and the UEFI installation? It can be a SUSE document or a book. Now I need to understand what I am doing so I can have a working--full sized computer again--tired of this laptop.
From an installation perspective, UEFI doesn't really change anything. UEFI and GPT partitioning are go-togethers, dispensing with the concept of partitions termed "logical", even though *all* storage device partitions are logical. Booting from UEFI depends on presence of a small FAT partition, the EFI System Partition, or ESP, with a minimum size of 100M for most installations, and a minimum size of 260M if the installation disk is 16T or more and has 4k sector sizes lacking 512b sector size emulation. Recommended size is all over the place, from the Windows minimum of 100M to sometimes 1000M or more. For typical installations, 500M, a common recommendation, means more than 90% of available space is wasted. Last I checked, the openSUSE installers complain that 100M is too small. That warning, if it appears, should be ignored. The ESP gets mounted to /boot/efi/. My own all have 320M, as they are all multi- multiboot. Every installed distro with an installed Grub will normally have its own ESP directory, when normally mounted, in /boot/efi/EFI/. It is from the ESP partition that boot actually begins, rather than from any disk's master boot record, by the EFI BIOS reading a file, most commonly grubx64.efi. Grub operation on UEFI differs mainly on its initial launching. The tools for maintaining it, and /boot/grub2/grub.cfg, are essentially the same, but a new one, efibootmgr, independent of Grub, has been added to inquire of and manage boot order in the UEFI BIOS - to configure the location of the file to be read to initiate boot. UEFI doesn't care what you install on any more than legacy. NVME partitions go by /dev/nvme#n#p## just like ATA HDDs & SSDs go by /dev/sdX##. NVME drives use a different driver than ATA drives, but that is of no concern to installation or users. Tools exist that are capable of converting MBR partitioning into GPT partitioning if that makes any sense to try, but typically because of the need for the new ESP or other reasons it's best to start fresh with a new table and new partitions. Most UEFI BIOS present an option that goes by various labels according to computer brand or BIOS developer, but should be labeled CSM or/for "Compatibility Support Module". To ensure installation occurs in UEFI mode, it's best that it be disabled, so that the installation media has no other option than to boot in UEFI mode. The UEFI installer omits the Fn key list at the bottom of its boot screen. Any necessary edits for booting the installer are done in same manner as with an installed Grub, strike the E key and add or remove as required before proceeding. They are mainly the same as always. Many are listed on https://en.opensuse.org/SDB:Linuxrc -- Evolution as taught in public schools is, like religion, based on faith, not based on science. Team OS/2 ** Reg. Linux User #211409 ** a11y rocks! Felix Miata